Plus, so many foods list what they "may contain" traces of X, but never really quantify how much of a trace. Which actually may be a good thing about intentionally adding sesame, because at least it makes the amount consistent.

I was allergic to peanuts as a kid, way back before it was cool, and didn't know why M&Ms gave me a mild version of the burning sensation and nausea I would get from eating peanuts. Later it turned out, famously, that non-peanut M&M shells contain some "reprocessed" material from the peanut M&M line. (And still do as far as I can tell.)

Nothing else with the "may contain" label has ever given me trouble! But I still get nervous that I'll find out 2 hours into a bike ride that I just fueled up on an extra peanutty "may contain" Clif bar.

Now I'm concerned about sesame. I can eat hamburger buns just fine but I discovered sometime in my 20s that sesame noodles make me sick, and the last time I was at a Korean restaurant my face puffed up just from the air.

So, oddly, one positive of the trend described in the story is that if processed food X lists sesame as an ingredient, and I can nibble on it and then eat the whole thing without getting sick, then I know whether or not I can eat that food, because it's presumably made with a consistent amount of sesame every time. Whereas with a "may contain" label, I'm never really sure if some batch might have lots of sesame and I just tested a non-sesame batch.